Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Liabilities [Abstract]
Insurance claims	$ 140,182	$ 127,029
Payroll and payroll-related	139,887	71,593
Interest payable	29,580	17,286
Final capping, closure and post-closure liability - current portion	20,023	3,680
Unrealized cash flow hedge losses	19,925	7,707
Cell processing reserve - current portion	3,344	3,518
Environmental remediation reserve - current portion	2,300	2,314
Share-based compensation plan liability - current portion	868	930
Other	48,814	46,751
Accrued liabilities	$ 404,923	$ 280,808

Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable in twelve months or in the next operating cycle if longer.

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Carrying value as of the balance sheet date of obligations incurred through that date and payable to insurance entities to mitigate potential loss from various risks or to satisfy a promise to provide certain coverage's to employees. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value of the obligation (known or estimated) to be incurred and payable in the next twelve months for the treatment and excavation of oilfield waste received.

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